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Introduction to RFIDIntroduction to RFID
RFID ProgrammingRFID ProgrammingUniversity of HoustonUniversity of HoustonBauer College of BusinessBauer College of BusinessSpring 2007Spring 2007
Some links…
www.rfidjournal.com www.computerworld.com www.rfidusa.com RFID Handbook www.uh.edu/gartner
Auto-ID Technologies
BiometricSystems
Smart Cards
RFID
OpticalCharacter
Recognition(OCR)
BarcodeSystems
Auto-ID
Definition
RFID (Radio Frequency Identification) is a technology used for electronic and wireless identification of objects, humans and animals
RFID History
“People say the Internet happened quickly. They’re crazy. It took forever!”
Robert Taylor
APRA IPTO Director
RFID History: Ancient TimesDecade Event
1940-1950
RadarHarry Stockman “Communication by Means of Reflective Power”, 1948
1950-1960
Early exploration“Identification, friend or foe” (IFF)
1960-1970
Further scientific explorationCompanies: Checkpoint, Sensormatic, KnogoElectronic Article Surveillance (EAS)
1970-1980
Explosion of RFID developmentApplications: animal tracking, vehicle tracking, factory automation
1980-1990
Commercial RFID applications enter mainstream
1990-2000
RFID becomes a part of daily lifeHarris County Toll Road Authority, 1992
Source: AIM, Inc, 2001 (URL: www.aimglobal.org/technologies/ rfid/resources/shrouds_of_time.pdf
Mandates
Mandates
Wal-Mart – An update October 2005
out of stocks reduced up to 16% out of stock items with EPCs replenished 3 times faster
stores with RFID 63% more effective in restocking items 10% less manual orders, reduced excess inventory
helps make sure that promotional displays are delivered and in place so that products are in our stores and ready for sale when the advertising begins
Shortens time for new items to make it to store shelves
Aids in proof of delivery & purchase order reconciliation - provides product visibility even after it has left receiving dock
> 600 suppliers expected to be on board by 2007
RFID Principal System Components Tag (Transponder)
Chip Antenna
Reader (Interrogator) RF Module (Transmitter and Receiver) Control Unit Antenna Several Interfaces (RS 232, RS 485, etc.)
Host Computer Middleware
RFID System Architecture
EPC RFID Architecture
EPC RFID System Architecture
Carrier Frequencies
What is frequency? Refers to the property of radio waves used to
transmit data
Carrier Frequency
RFID systems may use a particular frequency band depending on: Application Legislature Cost considerations
Frequency BandsFrequency Band Characteristics Typical
Applications
Low
100-500 kHz
Short to medium read range, inexpensive, low reading speed
Access control
Animal/Human identification
Inventory Control
Medium
10-15 MHz
Short to medium read range
Potentially inexpensive
Medium reading range
Access Control
Smart Cards
High
UHF: 850-950MHz
Microwave: 2.4 – 5.8 GHz
Long read range
High reading speed
Line of sight required (Microwave)
Expensive
Railroad car monitoring
Toll collection systems
Coupling
100kHz – 30 MHz – inductive coupling HF and Microwave systems use
electromagnetic coupling
Coupling
Frequency and bandwidth
Frequency is of primary importance when determining data transfer rates (bandwidth)
The higher the frequency, the higher the data transfer rate
Range
Range – the working distance between a tag and a reader
Range
Range and Power Levels
The range that can be achieved in an RFID system is determined by The power available at the reader The power available within the tag The environmental conditions and structures
More important at higher frequencies than at lower frequencies
100-500mW
Material Propagation
The absorption rate for water and other non-conductive substances is lower by a factor of 100 000 at 100 kHz than it is at 1 GHz
LF systems are primarily used due to their high propagation of substances
Electromagnetic Interference
Electromagnetic Interference - Interference caused when the radio waves of one device distort the waves of another. Cells phones, wireless computers and even robots in factories can produce radio waves that interfere with RFID tags.
EI is likely to be an issue for UHF systems
Tags Characteristics
Means by which transponder is powered Data carrying options Data read rates Programming options Physical forms Costs
Active and Passive Tags
Active tags Powered by an internal battery Finite lifetime (because of battery) Greater range Better noise immunity Higher data transmission rates
Active and Passive Tags
Passive tags Operate without battery Derive power from the field generate by the
reader Less expensive Unlimited life Subject to noise Require more powerful readers Orientation sensitivity
Data Carrying Options
A tag can contain An identifier
1bit – 128 bits Portable data files
Example: 64 K
Data Read Rate
Data read rate is linked to frequency The higher the frequency, the higher the read rate
Data Programming Options
Read-only Cheap
Write once read many (WORM) Read/write
Expensive
Why Use Read/Write Tags?
Greater flexibility Customers may change requirements Standards may change
Database dependence Ownership issues Lag times
High risk applications
Tag Physical Forms
Disk and Coins – can be attached to an item by a fastening screw
Tag Physical Forms
Mount-on-Metal – special construction minimizes impact of metal in terms of interference
Tag Physical Forms
Keys or Key Fobs, Watches – access control
Smart Labels
A bar code can be printed on an RFID label
Tag Physical Forms
Glass Transponders can be implanted under skin
What’s so special about RFID? Unifying Auto-ID technology Line of sight is not required Longer read ranges Faster: hundreds of items can be scanned in
one read
RFID vs. Barcodes
RFID Evolution (Gartner, 2003)
RFID Growth
Several market research firms predict that ~2007 RFID market will reach ~$3 billion
Questions?